Import multiple objects using python
Using BlendDataLibraries # bpy.data.libraries

import bpy

filepath = "//link_library.blend"

# append all objects starting with 'house'
with bpy.data.libraries.load(filepath) as (data_from, data_to):
    data_to.objects = [name for name in data_from.objects if name.startswith("house")]

# link them to scene
scene = bpy.context.scene
for obj in data_to.objects:
    if obj is not None:
        scene.objects.link(obj)